Database
BASIC ALGEBRAIC STRUCTURES
Monoids
Monoid homomorphisms and submonoids
submss
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submid
Metamath Proof Explorer
Ascii
Unicode
Theorem
submss
Description:
Submonoids are subsets of the base set.
(Contributed by
Mario Carneiro
, 7-Mar-2015)
Ref
Expression
Hypothesis
submss.b
⊢
B
=
Base
M
Assertion
submss
⊢
S
∈
SubMnd
⁡
M
→
S
⊆
B
Proof
Step
Hyp
Ref
Expression
1
submss.b
⊢
B
=
Base
M
2
submrcl
⊢
S
∈
SubMnd
⁡
M
→
M
∈
Mnd
3
eqid
⊢
0
M
=
0
M
4
eqid
⊢
M
↾
𝑠
S
=
M
↾
𝑠
S
5
1
3
4
issubm2
⊢
M
∈
Mnd
→
S
∈
SubMnd
⁡
M
↔
S
⊆
B
∧
0
M
∈
S
∧
M
↾
𝑠
S
∈
Mnd
6
2
5
syl
⊢
S
∈
SubMnd
⁡
M
→
S
∈
SubMnd
⁡
M
↔
S
⊆
B
∧
0
M
∈
S
∧
M
↾
𝑠
S
∈
Mnd
7
6
ibi
⊢
S
∈
SubMnd
⁡
M
→
S
⊆
B
∧
0
M
∈
S
∧
M
↾
𝑠
S
∈
Mnd
8
7
simp1d
⊢
S
∈
SubMnd
⁡
M
→
S
⊆
B